Conventional transmission pumps are driven by output from the engine in order to transfer hydraulic fluid and thereby meet cooling, lubrication, and pressure requirements of the transmission. The transmission pump includes a pump body which is stationary relative to the transmission housing, and a pump drive gear which is rotatable within the pump body to drive the pump. Rotational forces from the engine may be transferred to the pump drive gear via a torque converter hub. It is known that transmission pumps can leak, and that such leakage diminishes pump efficiency and vehicle fuel economy.